Wrist pin



June 23, 1964 J. D. MlLEs 3,138,040

wRIsT PIN Filednec. 27. 1980 Jose/:fr 00K: M785,

40 INVENToR.

/ farmy' Patented June 23, 1964 3,138,040 WRTST PIN .lcseph Dale Miles, 11017 Foxcroft Drive, Whittier, Calif. Fiied Dec. 27, 1960, Ser. No. 78,563 Claims. (Cl. 74-600) This invention relates generally to derrick apparatus and relates more particularly to wrist pins for pitmans such -as employed in pumping and drilling rigs in oil field work.

While the invention has particular utility in connection with pumping and drilling apparatus used in oil field work, and Vis shown 'and described in such connection, it is to be understood that its utility is not Confined thereto.

As is lwell known, the weight of the plunger and string of sucker rods and the oil being pumped is very great and is carried at one end of the 'walking beam of the pumping apparatus. The opposite end of the Walking beam is connected to the Crank pin or wrist pin of the pumping apparatus by means of the pitman, such Crank pin or wrist pin is subject to severe wear and heavy strains. Consequently, such pins fail after a relatively short period of use and must be replaced. Replacement of such wrist pins is a relatively difficult, time consuming and expensive procedure involving down-time, boring and sleeving, driving with the sledge, etc.

It is therefore an object of the present invention tov provide a Crank pin or wrist pin that may be readily installed on the Crank of oil drilling or pumping apparatus to replace worn or damaged Crank or wrist pins.

Another object of the invention is to provide a device of this Character that may be installed in a relatively short time and with a minimum of etfort.

Still another object of the invention is to provide a device of this Character that will fit present cranks of oil drilling or pumping equipment and take the place of present pins.

A still further object of the invention is to provide Crank or wrist pins of this Character adapted to fit cranks having two or more holes therein.

Another object of the invention is to provide pins of this Character that may be easily installed and which will eliminate the down-time, boring and sleeving, driving with a sledge, etc. of the procedure heretofore used in replacing Crank or wrist pins.

Still another object of the invention is to provide pins of this Character adjustable longitudinally of the Crank.

A further object of the invention is to provide Crank or wrist pins of this Character that are relatively simple in construction.

A still further object of the invention is to provide pins of this Character that are relatively inexpensive to manufacture.

Another object of the invention is to provide Crank pins of this Character that may be securely attached to the Crank of the pumping or drilling apparatus.

Still another object of the invention is to provide pins of this Character that have optimum of Crank engaging surfaces.

A further object of the invention is to provide pins of this Character that are rugged, strong and reliable.

A still further object of the invention is to provide pins of this Character that will have relatively long Operating life.

The characteristics and advantages of the invention are further sufficiently referred to in connection with the following detailed description of the accornpanying drawings, which represent certain embodiments. After considering these examples, skilled persons will understand that variations may be made without departing from the principles disclosed and I Contemplate the employment of any structures, or arrangements or modes of operation that ,are properly within the scope of the appended claims.

Referring to the drawings, which are for illustrative purposes only:

FIG. 1 is a side elevation with a portion of oil well apparatus including the Crank having the present invention operably secured thereto and to which the pitman of said apparatus is operably connected;

FIG. 2 is an enlarged section view through a portion of the Crank showing one embodiment of the present invention operably attached thereto;

FIG. 3 is a fragmentary view of the inner surface of one of the plates of the device;

FIG. 4 is a side elevation of an alternative arrangement; and

FIG. 5 is a side elevation of another -alternative arrangement.

Referring more particularly to the drawings, there is shown a portion of the oil well pumping apparatus, indi- Cated generally at 10, and including a walking beam 12 having the usual pitman 14 operably connected to one end thereof by means of the usual stirrup 16. The opposi-te end of the pitman 14 is connected to a Crank 18 attached to a shaft 20, said Crank having a plurality of openings 21 spaced longitudinally thereof. The shaft 20 is operably carried by support means 22 which may be of any well known Character. A counterbalancing weight 24 is Carried at the outer end of the Crank 18.

The present invention resides -in the means for Connecting the pitman to the Crank and said means is indicated generally `at 26. It is to be understood, of Course, that while this means 2.6 is adapted to replace the wrist pin that is original equipment the present device may also be provided as original equipment.

The connecting means 26 Comprises a shaft or pin 28 carried by a plate 30 to which said shaft or pin is attached by any suitable means such as welding or the like. These parts may, of course, be formed integrally.

Adjacent each end of plate 30 there is provided a bolt 32 which extends from said plate in a direction opposite the pin or shaft 28. Bolts 32 are spaced apart sufliciently to be received in the openings 21 at each side of the opening 21 which is aligned with the axis of said pin or shaft 28. A plate 34 is disposed on the bolts 32 at the side of the Crank 18 opposite the plate 30 and nuts 36 are threadably attached to the threaded free end portions 38 of said bolts 32, lockw-ashers 40 being disposed 'between said nuts 36 and plate 34.

The plates 30 and 34 may be termed clamping plates and are of sufficient size to substantially overlay parts of the Crank about the openings 21 in which the bolts 32 are disposed and the inner surfaces of the plates 30 and 34 which engage the adjacent parts of the Crank 18 are knurled, as shown at 42 in FIG. 3.

Shaft 28 has an axial bore 46 and plate 30 has a bore 48 which is an extension of the bore 46. Bores 46 and 48 reCeive a bolt 50 which extends through the opening 21 aligned with the aXis of the shaft 28 and also extends through an opening 52 in the Clarnping plate 34 aligned with the bores 46 and 48. The free end 54 of the bolt 50 adjacent the plate 34 is threaded for reception of a nut 56 and between nut 56 and plate 54 is a lockwasher 58. At the opposite end of the bolt 50 there is a washer 60 and the adjacent free end portion 62 of said bolt 50 is also threaded for reception of a nut 64. Between nut 64- and Washer 60 is a lockwasher 66.

The adjacent end of the pitman 14 is provided with a suitable opening 68 in which a shaft or wrist pin 28 is operably disposed and the washer 60 retains said pitman on said shaft when the nuts 56 and 64 are tight. The bolt 50 not only serves to retain the washer 60 in position and hold the pitman on the wrist pin 28 but also provides additional means for tightenng the clamping plates 30 and 34 on the Crank 18.

In FIG. 4 there is disclosed an alternative arrangement wherein the pin or shaft 28 is carried at one end of a clamping plate 30a while bolts 32a are attached in spaced relationship along said plate 34a. The bolt 54) is adapted to be disposed in an opening 21 of the Crank 18 while the bolts 32a are disposed in successively spaced openings 21 in the Crank. This arrangement is particularly useful when it is desired to have the wrist pin or shaft 28 at the end opening of a series of openings in the Crank. The bolts 32a function to securely tighten the plates 30a and 34 on the Crank 18, the bolt St) also aiding in clamping-y securing said plates on the Crank. Bolt 50 is the same as the bolt S in the arrangements shown in FIG. 2 and other parts of the device are also the same as in the arrangements shown in said FIG. 2.

Still another alternative arrangement is shown in FIG. 5. The clamping plates are indicated at 30h and 34a. clamping plate 301) carries the shaft or wrist pin 28 and also carries bolts 32 which are adjacent the respective ends of said plate 301). In this arrangement the pin or shaft 23 is solid and has a reduced diameter part '70 which extends axially from the free end thereof and is provided with a diametrical opening '72 in which a cotter pin 74 is operably received for retention of the washer 60 on said shaft 28. The clamping plates 30h and 34a do not have openings therein aligned with the axis of the shaft ZS, said bolts 32 with their nuts 36 being adapted to securely hold the device on the Crank, it being understood that the bolts 32 are received in openings 21 of the Crank. These bolts 32 may be received in openings 21 that are next to each other or they may be so spaced as to be received in openings 21 at opposite sides of an intermediate opening.

It is to be noted that the clamping plates 34 of the various arrangements are provided with openings 33 for reception of the bolts 32 and 32a. Said clamping plates are also provided with openings 52 for reception of the bolt S0.

It is thought that the invention and its attendant advantages will be understood from the foregoing description and that it will be apparent that various Changes may be made in the form, construction and arrangement of the parts of the invention without departing from the spirit and scope thereof or sacrificing its material advantages, the arrangements hereinbefore described being merely for purposes of illustration.

I claim:

1. The Combination of a Crank for oil well pumps and the like, said Crank having at least three longitudinally spaced holes therein, with a wrist pin comprising: a clamping plate; a shaft carried by said clamping plate and extending laterally therefrom at an angle normal to said plate, said shaft being supported only by said plate and having an axial bore therethrough; a pair of bolts secured to said plate adjacent the ends thereof and normal thereto in parallel relationship to each other and spaced apart longitudinally of said plate, said bolts being spaced for reception in said holes in said Crank said bolt being of substantially smaller diameter than the diameter of the holes for said bolts, one of said holes being positioned intermediate the holes for said bolts, said bolts having threaded outer free end portions; a second clamping plate having end openings removably receiving said bolts; nuts on the threaded end portions of said bolts for forcing the clamping plates toward each other to clampingly engage the adjacent sides of said Crank, said clamping plates being of sufficient size to overlie parts of the Crank about the Crank holes in which the bolts are received, the facing sides of said clamping plates being knurled and said clamping plates having openings therein aligned with the bore through the shaft; a bolt removably disposed in the bore through the shaft and the aligned openings in said plates; a washer of greater diameter than said shaft disposed on the last mentioned bolt at the free end of said shaft, the last mentioned bolt having at least one threaded end portion; and nut means on the threaded portion of the last mentioned bolt for securing said washer in position and providing additional clamping force for the clamping plates.

2. The Combination of a Crank for oil well pumps and the like, said Crank having at least three longitudinally spaced holes therein, with a wrist pin, Comprising: a clamping plate; a shaft carried by said clamping plate and extending laterally therefrom at an angle normal to said plate, said shaft being supported only by said plate and having an axial bore therethrough; a pair of bolts secured to and extending normal to said plate in parallel relationship to each other and spaced apart longitudinally of said plate, said bolts being spaced for reception in adjacent openings in said Crank, one of said holes being positioned adjacent to one of the holes for one of said bolts and adjacent to the hole aligned with the shaft bore, said bolts being of smaller diameter than the diameter of the holes for said bolts having threaded outer free end portions; a second clamping plate having openings spaced to removably receive said bolts; nuts on the threaded end portions of said bolts for forcing the clamping plates toward each other to clampingly engage the adjacent sides of the Crank, said clamping plates being of suflicient size to overlie parts of the Crank about the openings in which the bolts are received, the facing sides of said clamping plates being knurled and each of said clamping plates having an end opening therein aligned with the bore through the shaft; a bolt removably disposed in the opening through the shaft and the openings in said plates as Well as through Crank hole aligned with the shaft bore; a washer of greater diameter than said shaft disposed on the last mentioned bolt at the free end of said shaft, the last mentioned bolt having at least one threaded end portion; and nut means on the threaded portion of the last mentioned bolt for securing said washer in position and providing additional clamping force for the clamping plates.

3. The combination of a Crank of oil Well pumps and the like having a plurality of holes therein spaced longitudinally of said Crank with a wrist pin, Comprising: a clamping plate; a shaft secured to said clamping plate and extending laterally from one side at an angle normal to said plate, said shaft having a reduced diameter portion extending axially from the free end thereof; a pair of bolts secured to and extending normal to said plate in parallel relationship to each other and spaced apart longitudinally of said plate at the opposite side thereof, said bolts being spaced for reception in respective holes in said Crank, said bolts being of substantially smaller diameter than the holes for said bolts and having threaded outer free end portions; a second clamping plate having openings therein removably receiving said bolts; nuts on the threaded end portions of said bolts for forcing the clamping plates toward each other to Clampingly engage the adjacent sides of said Crank, said clamping plates being of sufficient size to overlie parts of the Crank about the openings in which the bolts are received, the facing sides of said clamping plates being knurled; a washer of greater diameter than said shaft disposed on said reduced diameter portion of said shaft; and means for retaining said washer in position on said reduced diameter portion.

4. The combination of Crank arm having a plurality of longitudinally spaced holes therein with a wrist pin, Comprising: a clamping plate; a shaft secured to said clamping plate and extending laterally from one side at an angle normal to said plate; a pair of bolts extending normal to said plate at the opposite side thereof in parallel relationship to each other and spaced apart longitudinally of said plate, said bolts being secured to said plates and being spaced for reception in respective holes in said Crank and being of suhstantially smaller diameter than the holes for said bolts, said bolts having threaded outer free end portions; a second clamping plate having openings removably receiving said bolts; nuts on the threaded end portions of said bolts for forcing the clamping plates toward each other to clampingly engage the adjacent sides of said crank, said clamping plates being of suflicient size to overlie parts of the crank about the openings in which the bolts are received, the facing sides of said clamping plates being knurled; a washer of greater diameter than said shaft disposed at the free end of said shaft; and means for securing said washer n position at said free end of said shaft.

5. In wrist pin means for the crank of oil well pumps and the like, said crank having a plurality of holes spaced longitudinally thereof: a clamping plate; a shaft secured to said clamping plate and extending laterally from one side at an angle normal to said plate, said shaft having an axial bore therethrough; a pair of bolts secured to the opposite side of said plate and normal thereto in parallel relationship to each other and spaced apart longitudinally of said plate and outwardly relative to the axis of said shaft, said bolts being of smaller diameter than the holes in a crank to which said wrist pin means is adapted to be attached, said bolts having threaded outer free end portions; a second clamping plate having openings for removable reception of said bolts; and nuts on the threaded end portions of said bolts for forcing the clamping plates toward each other, the facing sides of said clamping plates being knurled and said clamping plates have openings therein aligned with the bore through the shaft for reception of a bolt.

6. In wrist pin means for the crank of oil well pumps and the like said crank having a plurality of holes spaced longitudinally thereof: a clamping plate; a tubular shaft secured to said clamping plate and extending laterally from one side at an angle normal to said plate; a pair of bolts secured to said clamping plate and extending at an angle normal to said plate from the opposite side thereof in parallel relationship to each other and spaced apart longitudinally of said plate, said bolts being at one side of the axis of said shaft and spaced therefrom, said bolts being of smaller diameter than the holes in the crank to which said wrist pin means is adapted to be operably attached, said bolts having threaded outer free end portions; a second clamping plate having openings therein for removable reception of said bolts; and nuts on the threaded end portions of said bolts for forcing the clamping plates toward each other, the facing sides of said clamping plates being knurled and said clamping plates having openings therein aligned with the opening through the shaft for reception of a bolt.

7. In wrist pin means for the crank of oil well pumps and the like, said crank having a plurality of holes spaced longitudinally thereof: a clamping plate; a shaft secured to said clamping plate and extending laterally from one side at an angle normal to said plate, said shaft having a reduced diameter portion extending axially from the free end thereof and having a diametrical opening therethrough spaced outwardly of said free end of said shaft; a pair of volts secured to said plate and extending from the opposite side of said plate and normal thereto in parallel relationship to each other and spaced apart longitudinally of said plate and outwardly at respective sides of the axis of said shaft, said bolts being of smaller diameter than the holes into which said bolts are adapted to be operably disposed, said bolts having threaded outer free end portions; a second clamping plate having openings for removable reception of said bolts; and nuts on the threaded end portions of said blots for forcing the clamping plates toward each other, the facing sides of said clamping plates being knurled.

8. In wrist pin means for a crank arm having spaced openings therein: a clamping plate; a shaft carried by said clamping plate and extending laterally from one side at an angle normal to said plate; a pair of bolts extending from the opposite side of said plate and normal thereto in parallel relationship to each other and spaced apart longitudinally of said plate and relative to the axis of said shaft, said bolts being of smaller diameter than the spaced openings of the crank to which said wrist pin means is adapted to be attached, said bolts having threaded outer free end portions; a second clamping plate having openings for removable reception of said bolts; and nuts on the threaded end portions of said bolts for forcing the clamping plates toward each other, the facing sides of said clamping plates being knurled.

9. In wrist pin means for a crank arm having spaced openings therein: a clamping plate; a shaft supported at one end solely by said plate and extending laterally from one side of said plate at an angle normal thereto; a pair of bolts extending from the opposite side of said plate and normal thereto in parallel relationship to each other and spaced apart longitudinally of said plate and relative to the axis of said shaft, said bolts being of smaller diameter than the openings in which said bolts are adapted to be operably disposed said bolts having threaded outer free end portions; a second clamping plate having openings for removal reception of said bolts; and nuts on the threaded end portions of said bolts for forcing the clamping plates toward each other, the facing sides of said clamping plates having means for holding said plates against slippage when said wrist pin is operably secured to a crank arm.

10. In wrist pin means for a crank arm having spaced openings therein: a calmping plate; a shaft carried by said clamping plate and extending laterally from one side at an angle normal to said plate; a pair of bolts on said clamping plate extending from the opposite side of said plate and normal thereto in parallel relationship to each other spaced apart longitudinally of said plate and relative to the axis of said shaft, said bolts being of substantially smaller size than the openings into which said bolts are adapted to be operably disposed, said bolts having threaded outer free end portions; a second clamping plate having openings for removable reception of said bolts; and nuts on the threaded end portions of said bolts for forcing the clamping plates toward each other, the facing sides of said clamping plates being knurled.

References Cted in the file of this patent UNITED STATES PATENTS 1,706,909 Wirt Mar. 26, 1929 1,891,403 Dailey Dec. 20, 1932 3,033,588 Muller et al May 8, 1962 

1. THE COMBINATION OF A CRANK FOR OIL WELL PUMPS AND THE LIKE, SAID CRANK HAVING AT LEAST THREE LONGITUDINALLY SPACED HOLES THEREIN, WITH A WRIST PIN COMPRISING: A CLAMPING PLATE; A SHAFT CARRIED BY SAID CLAMPING PLATE AND EXTENDING LATERALLY THEREFROM AT AN ANGLE NORMAL TO SAID PLATE, SAID SHAFT BEING SUPPORTED ONLY BY SAID PLATE AND HAVING AN AXIAL BORE THERETHROUGH; A PAIR OF BOLTS SECURED TO SAID PLATE ADJACENT THE ENDS THEREOF AND NORMAL THERETO IN PARALLEL RELATIONSHIP TO EACH OTHER AND SPACED APART LONGITUDINALLY OF SAID PLATE, SAID BOLTS BEING SPACED FOR RECEPTION IN SAID HOLES IN SAID CRANK SAID BOLT BEING OF SUBSTANTIALLY SMALLER DIAMETER THAN THE DIAMETER OF THE HOLES FOR SAID BOLTS, ONE OF SAID HOLES BEING POSITIONED INTERMEDIATE THE HOLES FOR SAID BOLTS, SAID BOLTS HAVING THREADED OUTER FREE END PORTIONS; A SECOND CLAMPING PLATE HAVING END OPENINGS REMOVABLY RECEIVING SAID BOLTS; NUTS ON THE THREADED END PORTIONS OF SAID BOLTS FOR FORCING THE CLAMPING PLATES TOWARD EACH OTHER TO CLAMPINGLY ENGAGE THE ADJACENT SIDES OF SAID CRANK, SAID CLAMPING PLATES BEING OF SUFFICIENT SIZE TO OVERLIE PARTS OF THE CRANK ABOUT THE CRANK HOLES IN WHICH THE BOLTS ARE RECEIVED, THE FACING SIDES OF SAID CLAMPING PLATES BEING KNURLED AND SAID CLAMPING PLATES HAVING OPENINGS THEREIN ALIGNED WITH THE BORE THROUGH THE SHAFT; A BOLT REMOVABLY DISPOSED IN THE BORE THROUGH THE SHAFT AND THE ALIGNED OPENINGS IN SAID PLATES; A WASHER OF GREATER DIAMETER THAN SAID SHAFT DISPOSED ON THE LAST MENTIONED BOLT AT THE FREE END OF SAID SHAFT, THE LAST MENTIONED BOLT HAVING AT LEAST ONE THREADED END PORTION; AND NUT MEANS ON THE THREADED PORTION OF THE LAST MENTIONED BOLT FOR SECURING SAID WASHER IN POSITION AND PROVIDING ADDITIONAL CLAMPING FORCE FOR THE CLAMPING PLATES. 